Peak oil doomers suggests that humanity’s over reliance on petroleum for agricultural and industrial productivity will cause severe problems on the down-slope of peak oil. By contrast a “peakist” would be one who has a lighter view on the implications of peak oil, although this label has been dismissed from within the movement as vacuous.”Boomsters” takes the opposite, cornucopian position.

A convinced doomer believes that the Green Revolution will collapse at the end of cheap oil. According to doomers, humanity will be in a state of overshoot after oil depletion makes modern farming methods economically non-viable. Various academics have calculated that our numbers would then far exceed the carrying capacity of the earth. For example: they believe our situation is comparable to bacteria in a petri dish with cheap oil as the human growth medium. As the “growth medium” is consumed and runs out the “bacteria” die off.

Doomers also hold a wide range of theories about the collapse of complex societies and systems.[4] The influences of Paul R. Ehrlich and the Club of Rome are present in the doomer movement, as are some of the more recent works by Joseph Tainter who wrote The Collapse of Complex Societies in 1988, and Richard C. Duncan who presented his Phd The Peak of World Oil Production and the Road to the Olduvai Gorge in 1989 (now known as the Olduvai theory.) The lectures and DVD by Albert Allen Bartlett, Arithmetic, Population and Energy are also highly influential.

The common concerns are that of overpopulation leading to resource and energy depletion, soil degradation and environmental destruction all culminating in agricultural collapse and famine. Some doomers estimate that the anarchic collapse will be so catastrophic that population levels may fall below the levels prior to the industrial revolution — possibly below 2 billion. When trying to calculate the extent of the postulated dieoff, the most extreme doomer will also take into account that the existing eco-infrastructure is massively supported by oil based fertilizers and that we will not only hit peak oil but peak phosphate and peak nitrogen simultaneously. When oil production starts to decline the productivity of the soil will drop far below that of pre-industrial times and thus a drop down to 2 billion is optimistic. This kind of doomer will also ignore technology and dismiss it with commonly believed ideas such as “wind farms cost more energy to build than they get out”. This common refrain is generally applied to all technology solutions since it is assumed a priori that a population crash is inevitable.